Heater Core Temperature Sensor / Switch: Description and Operation

GF83.57-P-2134RC Heat Exchanger Temperature Sensor, Component Description

Component Identification:

Location
The heat exchanger temperature sensors are located in the air flow downstream of the heater heat exchanger in the heater or air conditioning housing below the instrument panel.

Task
The heat exchanger temperature sensors record the actual temperature of the air flow downstream of the heater heat exchanger.

Function
The heat exchanger temperature sensors are temperature-specific resistors. The heat exchanger temperature sensors are read in by the automatic heater control and operating unit (N18) (without code (580) Automatic air conditioning and without code (581) Comfort automatic air conditioning), by the AAC [KLA] control and operating unit (N22) (with code (580) Automatic air conditioning) or by the comfort AAC [KLA] control and operating unit (N22/7) (with code (581) Comfort automatic air conditioning).
A comparison takes place here between the measured temperatures (actual value) and preselected specified temperatures (specified value). The duo valve (Y21) opening time is calculated using the comparison of actual and specified value and is then actuated accordingly by the control and operating unit.